Abstract
In studies on streptococcal fibrinolysin it would be distinctly advantageous to have available a stable fibrinogen which could be maintained under storage conditions for a reasonable period.
Recently, Pomales-Lebron and Morales-Otero 1 have reported a technique for preserving whole plasma by a method involving freezing and desiccation in a high vacuum. Such preserved plasma, although shown to be suitable for fibrinolysis studies over a period of 8 months, must be secured from donors whose plasma is known to be susceptible to fibrinolysis. An obvious disadvantage of the method is that donors must be selected on the basis of a satisfactory preliminary test. Furthermore, we have observed that plasma clots much more slowly and undergoes lysis more slowly than does isolated fibrinogen.
Since the isolated fibrinogen fraction apparently does not carry the resistance factor which is present in many individuals, it is evident that pooled plasma from several individuals would constitute a satisfactory and convenient source of material if a method were available for preserving the. isolated fibrinogen. Ferguson and Erickson, 2 in studies on blood coagulation, have preserved a highly purified fibrinogen, prepared from dog plasma, by a rather elaborate technic, involving prefreezing and subsequent desiccation in special apparatus. Fibrinolysis studies have not been reported with their product.
This report embraces the details of a simple method for isolating and preserving fibrinogen in such a state that it can be stored for considerable periods of time, maintaining all the while the ability to redissolve, and upon addition of thrombin, to yield a clot suitable for the determination of fibrinolysin in streptococcus cultures. The method is as follows: 1. Pooled plasma is diluted with an equal volume of distilled water, and filtered through a Seitz or Berkefeld filter.
Get full access to this article
View all access options for this article.